I am trying to read the input from a barcode scanner that behaves like a keyboard using the hidapi (https://github.com/signal11/hidapi). Apparently the OS does not allow me to access the scanner because it behaves like a keyboard and for security reasons the OS owns all the keyboard and mice devices. The manufacturer of this barcode scanner does not provide any drivers. Is there a way to prevent the OS from owning this barcode scanner or maybe a way to turn it into a serial port and read from it?
In case there is no workaround for this, does anyone know a cheap barcode scanner that does not behave like a keyboard so that I can use the hidapi to access it? Or how can I know that a barcode will not behave like a keyboard? It is a very specific question that most sellers don't know how to reply.
Thanks.
A device that only simulates keyboard input, such as a barcode scanner, does not have a way to control programmatically, rather than an interactive device such as a game controller.
You just wait for the barcode data to be notified as keyboard input data.
It will notify you even if you do not own the device. In other words, you need to own keyboard focus. It is ordinary Windows programming knowledge.
Many keyboard input barcode scanners have the ability to customize prefix / suffix codes that are appended to the front and back to identify barcode data input.
They can be customized by reading the settings barcode.
Check the notified key code one by one in the application program, and if such special data comes, please treat it as barcode data.
By "OS" do you mean Windows? Other operating systems usually provide a means to intercept keystrokes. Linux, for example, has the input subsystem which lets you intercept keyboard events like keys being pressed and released. Unfortunately, these leave it to you to convert to ASCII/UTF-8 characters yourself.
An easier option, regardless of OS, may be to look for a barcode scanner that emulates a USB-Serial device. That would appear to the system as COMx in Windows, /dev/ttyUSBx in Linux, etc. Then you can just read the data from it using a serial port library and not worry about keyboard focus.
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I have a feeling I know the answer to this question, but it's been surprisingly difficult to confirm it anywhere. Is it possible to get raw keyboard and mouse input post-Catalina without needing "Input Monitoring" access in the Security & Privacy preferences?
I've never programmed a game engine before on macOS, but so far as I can tell, the "usual" way for games to get raw mouse deltas and raw keyboard states has been to use IOKit's HID API. Up until recently, this apparently was also the only way to get input from Xbox and Playstation gamepads.
When I attempt to use the IOKit HID API to get mouse and keyboard input, I receive a prompt to allow Input Monitoring in Security & Privacy preferences. Elsewhere on the internet, I've learned that this is due to a change in macOS Catalina: to use IOKit HID input handling, you now need the Input Monitoring permission. As far as I'm concerned, it's a deal-breaker for my game to require users turn this on.
Am I understanding this situation correctly? And if I am, is it just not possible to get raw (unprocessed) keyboard and mouse input without the Input Monitoring permission? I mean, I can hack together a solution for FPS-style mouse input using mouseMoved: events and the like, but such a solution would disallow sub-pixel precision and would subject my game to macOS's cursor acceleration. Is there another solution that games/game engines use?
If you’re willing to take on the macOS 11 requirement, it seems like Apple added raw keyboard and mouse support to the Game Controller framework. Seems to even support caps lock.
https://developer.apple.com/documentation/gamecontroller/gckeyboardinput?language=objc
I own a keyboard that has an anti-ghosting mode.
It is toggled on/off using Fn+ScrollLock. When on, the codes sent are a bit different. The keyboard is still legitimate HID, but, for example, all modifier keys are seen by Linux as Shift and the actual modifier key is in another field of the event.
What I am looking for is either a ready driver (should someone happen to know about one) or some introduction to writing such input drivers. I do not know much about the ecosystem (evdev, libinput, etc.) and I do not even know where to start. If possible, the same driver should work both under X11 and under Wayland.
Just for the record, the keyboard's “shop” name is Modecom Volcano Gaming. The USB ID is258a:1006 and it is apparently not annotated in usb.ids. The keyboard works perfectly fine in both modes under Windows.
I'm looking for a script or a program that runs in background and blocks special keys on my keyboard (calculator, mute, etc) I have searched a lot on this on the internet but didn't found anything useful or working for me, I tried sharpkeys but didn't detected those keys on my keyboard, key id is 173 for mute on my keyboard and I can get others IDs if I find anything to block them with IDs.
P.S. I don't know much about programming and most likely don't know what I am doing, I'm looking for basic help from anyone. thank you!
TL;DR To disable all "special keys" you could change the Human Interface Device Access Windows service startup type from Automatic to Manual (or Disabled in case there is some other software installed that causes it to still start when set to Manual). Caution: this may break other input devices if present, such as IR remote controls, or Airplane mode radio management.
For background, those "special keys" are technically called "consumer control buttons (CCB)" (see for example Keyboard Enhancements in Windows 8 and the linked .docx - nevermind that CCBs long predate Windows 8).
The CCBs are handled by the Human Interface Device Access Windows service, as described at Human Interface Device Access:
This service provides generic access to specific functions contained within controls collections on HID (Human Interface Devices). It enables the use of predefined hot buttons on keyboards, remote controls and other multimedia devices.
If the service is stopped or disable, the buttons on USB keyboards will not function (i.e., back, forward, volume up, down, previous track, next track), nor will the volume buttons on USB speakers.
To change the Human Interface Device Access (HidServ) startup mode, navigate to My Computer / Manage / Services and Applications / Services, double-click the Human Interface Device Access in the list, and change the Startup type to Manual or Disabled.
To disable special keyboard keys via registry on Windows 10 go to HKLM:\SYSTEM\CurrentControlSet\Services\hidserv and change "Start" DWORD value to 4. Once you restart the system, special function keys should be disabled.
I have two keyboards connected on my computer. I want to use one for the main keyboard, and another for a specific application. For example, keyboard #1 is used for Windows, and keyboard #2 is used only in my application.
Is it possible? If yes, which language should I use? Do I need to access to the driver? I precise that I'm running under Windows...
I found a link that explain step by step how to intercept keyboard keys, and how to identify the device that sent the keystroke.
Using Raw Input from C# to handle multiple keyboards
This example uses C# language.
Is there a way to programmatically find out what kind of keyboard a computer has (i.e. where keys are located, and what extra keys are present in which locations)?
A little error is acceptable, if the keyboard is very non-standard, but in general, the point is to construct an on-screen keyboard-like application that can dynamically draw the keyboard layout on the screen, with high accuracy.
when connected to a computer, keyboards sends "scan codes" to the operating system. on windows, scan codes are then converted into virtual keys (a hardware independent mapping of the keyboard) then to real characters.
the MapVirtualKeyEx() function of the windows API allows you to translate between scan codes, virtual keys and characters. it should also be able to tell you if a key is non-existing.
together with GetKeyboardLayout() which tells you which keybaord is active at any point in time (keyboard layout can be different for different running applications), it should allow you to build a pretty accurate map of the keyboard.
anyway, have a look at the keyboard input section of the MSDN
i will add that all keyboards have almost the same layout. although there is no way to know where a key is physically located, you can probably guess from the scan code and basic knowledge of your own keyboards.
There is no mechanism by which a keyboard can tell Windows what its physical layout looks like. Easy to see with the Windows version of an on-screen keyboard, osk.exe. It seems to be able to guess the form-factor of the machine (laptop vs desktop) but on my laptop it doesn't match the layout of the keyboard.
Use the osk.exe layout as a template so nobody can complain that yours doesn't match well.